Terrestrial communications systems continue to provide higher and higher speed multimedia (e.g., voice, data, video, images, etc.) services to end-users. Such services (e.g., Third Generation (3G) services) can also accommodate differentiated quality of service (QoS) across various applications. To facilitate this, terrestrial architectures are moving towards an end-to-end all-Internet Protocol (IP) architecture that unifies all services, including voice, over the IP bearer. In parallel with such terrestrial architectures and systems, mobile satellite systems are being designed to complement and/or co-exist with terrestrial coverage depending on spectrum sharing rules and operator choice. Among such mobile satellite systems, 3G UMTS-based networks using terrestrial 3G protocols have been widely deployed all over the world.
Terrestrial and satellite telecommunications services, rely on protocols and networking architectures that offer great flexibility and robustness. Mobile satellite systems advantageously use terrestrial 3G protocols in non-access stratum to allow interaction with terrestrial core networks and exploit widespread availability of terrestrial protocol stacks in user terminals. With regard to security, the terrestrial 3G protocols used by mobile satellite systems include security aspects such as SIM-based authentication, authorization and key agreement protocols. Radio access stratum in mobile satellite systems are typically optimize for the satellite environment, and therefore tend to be different than their terrestrial counterparts. Satellite base stations in user terminal chipsets that incorporate access stratum protocols and functions specific to satellite operation are readily developed and deployed. The access stratum security itself, however, is based on keys generated via the terrestrial 3G non-access stratum protocols, and hence rely on current states of such terrestrial 3G protocols (e.g., protocols based on 128 bit keys).
Moreover, applications and services requiring a high level of security (which at one time were addressed through proprietary segregated and highly secure systems and architectures (e.g., military and law enforcement systems), increasingly rely on broader-based commercial systems. Mobile satellite communications systems, based on their ability to reach diverse geographic regions without investment in significant ground-based infrastructure, are widely used for such high-security systems (e.g., military and law enforcement systems). This allows such high security services to be able to interoperate with broad-based commercial systems, and leverage the technology advancements and extensive infrastructure of such systems. Along with the proliferation of such high-security services, and the associated advancements in supporting technologies, security risks remain an ever-increasing threat. Accordingly, there is an ever increasing need for continued development of security architectures and protocols to combat such security risks.
There exists an increasing need, therefore, for improved security protocols in such 3G mobile satellite systems (e.g., security protocols based on extended key lengths).